🚀 go-pugleaf

Remy Lebeau (TeamB) wrote:
> C++Builder comes with its own copy of the Win32 help files, and you can
> always just look everything up at MSDN online directly.

I've got only the free command line tools because I'm a poor student who 
learns C for selling programms, so that I'll have enough money to buy 
the Builder.

> You didn't include the EXE's actual code at all.  You are not showing how
> you are actually allocating the buffer that you want your DLL function to
> fill in.  You're allowing any arbitrary buffer to be passed in from the EXE,
> but the DLL is assuming its own buffer size instead of allowing the EXE to
> tell the DLL exactly what the buffer size really is.

I think I found the mistake. In my exe, buffer was defined under the 
name lpPersonal as char*, but I set no explicit size. I came to this, 
because of your hint and the fact, that the program always crashed when 
I tried to access the buffer inside the exe. Inside the DLL, I'm able to 
show the buffer as MessageBox text.

> In fact, looking over this code, you are not assigning any kind of actual
> value to your buffer size in the first place.  You declared your buffer size
> as a pointer that you never actually assign to point to anywhere meaningful.
> As such, you're going to have any sort of potential problems when you are
> using the value later on because it is not valid to begin with.
> 
> I would suggest the simpler of the two possible solutions - just get rid of
> your buffer size variable from the DLL altogether and let the function
> accept an additional parameter so the EXE call specifically tell the DLL
> exactly what the buffer size already is:
> 
>     int __stdcall getShellFolder(int folder, char *buffer, DWORD buffersize)

What can the DLL to with this third parameter? It can see, that the 
buffer maybe to small.

Yours,
-- 
Robert Bienert <robertbienert@gmx.net>
Check also my free software at http://www.rbprogs.de.vu/